The present invention relates generally to the field of vacuum cleaners and specifically to a vacuum cleaning apparatus and method exhibiting a high efficiency in air flow management and utilization.
A broad array of household and industrial vacuum cleaners are known in the art. These machines generally include a vacuum source, such as an electric motor, a debris repository, such as a bag or canister for the collection of debris removed from the floor, and at least one inlet through which debris removed from the floor travels in an air stream to the debris repository. In a common configuration, the vacuum cleaner includes a single large inlet positioned over the floor, with a roller or xe2x80x9cbeater brushxe2x80x9d positioned within the inlet for agitating the surface of the carpet or other floor covering. These types of vacuum cleaners are inefficient at removing debris from the floor, as the large debris inlet area produces a very low airflow velocity. The airflow does not accelerate until it enters the smaller diameter tube or passageway connecting the inlet to the debris receptacle. Additionally, the action of the beater brushes produces unnecessary wear and tear on the carpet.
Another class of floor cleaning machines well known in the art deposit and subsequently remove cleaning fluid. The cleaning fluid, containing dirt and debris from the floor suspended therein, is removed from the floor by a vacuum action and transferred to a fluid recovery receptacle. Many of these floor cleaning machines have the vacuum inlets arranged on one or more rotating heads. The vacuum inlets on such machines, however, are optimized for the recovery of fluids from the floor, and not the direct removal of debris therefrom in an air stream. As such, they are often oriented at an angle other than parallel to the floor, and often contact the floor surface directlyxe2x80x94both of which reduce the ability of such machines to remove debris from the floor in an air stream without the use of fluids.
The present invention, in one aspect, relates to a vacuum cleaner for removing debris from a floor. The vacuum cleaner includes a vacuum source, a debris repository, a plurality of debris inlets that are maintained in spaced relationship to the floor, and a debris transport passage. The debris transport passage has a minimum cross-sectional area that is greater than or equal to the combined area of the debris inlets. The debris transport passage connects the debris inlets to the debris repository and carries debris from the floor in an air stream generated by the vacuum source.
In another aspect, the present invention relates to a method of vacuuming a floor. The method includes maintaining a plurality of debris inlets in spaced relationship over the floor, where the debris inlets are in airflow communication with a debris receptacle via a debris transport passage that has a cross-sectional area not less than the combined area of said debris inlets. Additionally, the method includes generating an air flow, resulting from a vacuum source, from the debris inlets to the debris receptacle, and moving the debris inlets over the floor in a generally parallel orientation with respect to the floor, so as to collect debris from the floor in the maximal velocity air flow.